6 Jul 2014

6 July 14 - A Flock Of Dorset Swallowtails - Mug Shots Of The Different Individuals

After a frustrating day of stiff SW winds & overcast conditions, it was no surprise that nobody appeared to have been out looking for the St Aldhelms Swallowtails on Saturday (5th). Sunday morning (6th), the wind had dropped & there seems to the hint of sun coming through the clouds. So I decided to head back to St Aldhelms to have another look for the Swallowtails as 3 different individuals had been seen on the Friday (4th). I've seen photos of two of these on twitter & both were very tatty looking & superfically looked different to the individuals George Green & I had photographed on Emmetts Hill on 30 June & 2 July, respectifully. As the Friday individuals were very close to the Coastguard lookout & a good 1/4 mile East of my Swallowtail on Emmetts Hill & there is a deep valley separating Emmetts Hill from the Coastguard lookout area, I thought they would be different individuals. However, it's more complicated than that as the photos reveal.

Very few Butterflies were on the wing on the Emmetts Hill path in stronger onshore winds. I carried onto the coast path close to the Coastguards lookout and met up with a couple who had been looking for some time without any joy. Fortunately, the sun finally came out & the wind dropped a bit. After about 15 minutes, I picked up one flying about 50 metres away. A quick jog & we could see this was a pretty fresh individual with just a little wing damage to the trailing edge of the right forewing. After that the sun stayed out nearly all the time. Occasionally the wind
picked up, but generally dropped fairly quickly again, although there
was always a breeze. The Butterflies then started to flying in response
to the improving weather. In the end, I photographed 2 more tatty
Swallowtails.

At one point, we were watching one flying when it met another & they
both spiralled high to about 40 metres above our heads, until they caught the wind & were rapidly
blown about 200 - 300 metres East before coming down close to the edge
of the crop field & rough grass near to the Radar Memorial. I'm not
sure if this was 2 males meeting or a pair displaying to each other.
About 2 or 3 minutes afterwards, we saw 2 individuals further along the
coast path. There wasn't the time for the spiralling two to have made it
back, so this makes 4 individuals present on the 6th. In the 4 hours I was
there, I saw this spiralling behaviour on 3 occasions & on each time
they ended up dropping in the same area. But I think they were eventually making it
back to where we were looking. But this behaviour, perhaps helps to
explain why they were going missing for 15 - 30 minutes at a time.

I'm now going to pull all these photos together in one place to try to document the different individuals present. Photos are my own, unless indicated as another photographer who has given me permission to put these photos on the blog & the copyright remains with the original photographer. Many thanks to those photographers for helping to clarify the numbers of Swallowtails present. I have labelled them in the order that I've become aware of the photos & have tried to add additional photos to show how they have worn over the following days. Unfortunately, I've not seen the photos taken of the other 2 individuals taken by the original couple who showed them to George on the 30th June. They were also a couple of sightings on the previous 2 days, but I haven't heard if these were photographed.

I will also give the details why I think each individual is different. It is clear that the hindwings are wearing more than the forewings & so I think the key features to look for are the forewing markings as well as the overall details of wear.

On a visit, it is worth looking in detailed at patterns in wear to identify individuals. However, this can still be misleading e.g. on the first day I saw Swallowtail B on 30 June, it initially had two tail spikes (albeit the right hand one was loose). In then flew off & came back on a few occasions & within 45 minutes, the tail spike had broken off naturally. Therefore, I've been tending to focus on notches in the fore wings as the most precise way to identify individuals in the field (by blowing up my photos on the back of the camera to check the fine detail). Once I get home then I can confirm my initial field opinions, by checking the forewing patterning as detailed below.

Swallowtail A (Emmett Hill individual)

Swallowtail A: A fresh individual photographed on Emmetts Hill (30 June 14 taken by George Green - Copyright remains with George & many thanks for allowing me to put this photo on my blog)

This individual was already looking tatty when I photographed it. But it is a different individual to George's as there are subtly different black markings on the forewing. I have more photos of it on the 2nd July on my original Swallowtail post & these photos show a before & after photo over a 45 minute period during which time it disappeared & reappeared without its right hand tail spike.

Swallowtail B: Left forewing (2 July 14) - Yellow patch A is almost square (Swallowtail A - it a longer & flattened oval) & black band C has 3 distinct triangular edges on left hand side (Swallowtail A - it's smooth)

Swallowtail B: Right forewing (2 July 14) Yellow patch A is circular (Swallowtail A - it's almost rectangular) & black band C is smooth edged & fat (Swallowtail A - it's smooth edged, but narrows away from the wing edge)

This individual has now moved back to St Aldhelms which surprised me, but perhaps explains why nobody has seen any Swallowtails on Emmetts Hill since the 2nd. Up to the 2nd the wind was Easterly or South Easterly, but since then it has switched to South Westerly & blowing stronger onto Emmetts Hill. Thus it is more exposed & perhaps that explains why Swallowtail B has moved back to just West of the Coastguards lookout on St Aldhelms.

Swallowtail B: The same individual photographed at St Aldhelms (4 July by Roger Musgrove - Copyright remains with Roger & many thanks for allowing me to put this photo on my blog)

Swallowtail B: The same individual, but now looking even more tatty. It is not easy to see much on the hindwings, but blow up of the forewings confirm it's is still the same individual (St Aldhelms on 6 July 14)

Swallowtail B: The same
individual, but now looking even more tatty. It is not easy to see much
on the hindwings, but blow up of the forewings confirm it's is still the
same individual (St Aldhelms on 11 July 14)

Swallowtail B: Not very useful for identification, but it's the only underwing & body shot I've got so couldn't resist adding it (St Aldhelms on 6 July 14)

Swallowtail C (St Aldhelms individual)

Swallowtail C: A worn individual photographed at St Aldhelms (4 July 14 taken by Roger Musgrove - Copyright remains with Roger & many thanks for allowing me to put this photo on my blog)

Swallowtail C: Left forewing (4 July 14 taken by Roger Musgrove). The black mark in cell D is small & distinctively shaped (compared to large & long in individual A)

Swallowtail C: Right forewing (4 July 14 taken by Roger Musgrove). The black mark in cell D is small & distinctively shaped (compared to large & long in individual A)

Clearly, this isn't individual B as it has more extensive hindwings than B & was photographed on the same day as individual B. It can also be ruled out from individual A by the distinctively small markings in cell D on each wing. It has a distinctive patch missing on the right forewing tip.

Swallowtail D (St Aldhelms individual)

Swallowtail D: A fresh individual with slight forewing damage to the right hand trailing edge & the left hand hindwing. Photographed at St Aldhelms (6 July 14)

This
individual looks like it was fairly freshly hatched. If so, then it would help eliminate a release after a wedding at the chapel given how fresh it is looking (compared to the others seen on the 6th). This is clearly not individuals B & C as it's fresh (see their photos from the 6th). It can also be confirmed as different to individual A as detailed below. On the 6th, it was looking very fresh, except for some fine damage to the trailing edges near the forewing tips (especially on the right wing) & a distinctive triangular notch on the left hindwing (but I'm sure that will wear move over the next few days.

Swallowtail D:
Left forewing (6 July 14) - Yellow patch A is more rounded (Swallowtail A -
it's longer & flattened) & black band C has distinctly
notched especially on the right hand side (Swallowtail A - it's smooth)

Swallowtail D:
Right forewing (6 July 14) - Yellow patch A is a flattened circle (Swallowtail A -
it's rectangular) & black band C has a distinct
shape & is very bulging near the front of the wing (Swallowtail A - it's smoother)

Swallowtail D: Hindwings (6 July 14) - This currently has a distinctive triangular notch in the rear left hand hind wing

I only succeeded in getting one decent shot of this worn individual. This still has a distinctive tail spike on it's right hindwing. If any other photographers who were there on the 6th have photos, I would appreciate more copies, especially as I can't do much on the left wing with my photo. Clearly, it is not as worn as individual B and isn't the fresh individual D (both photographed on the 6th) & hasn't got the missing right forewing tip of individual C. That just leaves individual A to eliminate which can be done on the right wing markings.

So based upon the photographic evidence, there have currently been 5 individuals present in the St Aldhelms Head & Emmetts Hill area. If any other photographers have photos of other individuals that they are happy for me to add to this collection, please leave me a Comment with your email address. I won't publish the Comment, but will contact you offline for the photos to continue this analysis. Finally, a big thanks to George Green & Roger Musgrove for sharing their photos for this analysis.

Watch the Comments as I will update that as I hear of updates on sightings of known individuals or general sightings. I will update the main post, if additional individuals are found.

7 comments
:

At least 3 have been seen at St Aldhelms today. This includes individual D and 2 others seen more briefly but not photographed. Additionally, one was briefly seen on the Emmetts Hill path to Chapmans Pool.

Swallowtails are still being seen at St Aldhelms. A number of people have seen inidividuals this week, but I've not seen photos. These are the ones I've seen photos to confirm the individuals involved:-Wednesday 9th - 2 possibly 3 were seen around the Coastguards area. Individual D was the only one I've seen photos of. It was still looking very similar to it did on the 6th (per Mark Tutton)Thursday 10th Individual B was still flying & is even more tatty now (per Brian Arnold)

Individual B was still present early afternoon Friday 11th. Seen several times over about 1 hour just West of the coastguards. I'll update the post over the weekend with an up to date picture of how it's looking at the moment.

Update from George Green today. There was a small concern when the Swallowtails were first found that they had been released after a wedding at the St Aldehelms chapel. Apparently, it's a trendy thing to release some Butterflies after a wedding. Although this is something that clearly isn't a good idea, whether native or non native species, it's an occasional thing that does happen. Anyway, this has been checked with the Revd Gaynor Burrett who covers the chapel & she has confirmed that no Swallowtails have been released over the 3.5 years she has been responsible for the chapel & Langton Matravers church. So that's good confirmation.

I've also been in touch with Michael Blencowe in Sussex who has been coordinating the Sussex sightings & also looking at other UK sightings. Up to a few days ago, he was aware of 29 in the UK being seen in 2014 inc from Kent, Sussex, Hants/Sussex border, the Isle of Wight, Devon & of course Dorset.

About Me

I've been a keen British birder since the age of 13. These days I
generally bird locally around Poole Harbour, the Purbeck coastline &
Dorset sites. However, the twitching urge from the late 70s hasn't left
& I will quickly go for ticks in the UK & Ireland. The recent Two-barred Greenish Warbler & Elegant Tern (2017) & BOU (IOC) taxonomy have brought the UK/Irish list up to 534 BOU (IOC)/IRBC. 5 species have only been seen in Ireland. Note, the Pasty-pouched (Dalmatian) Pelican is still pended.I started an English List a few years ago for a bit of fun, as it has only been since 2009 that I've started twitching Scotland & Scottish isles. A run of Ticks in 2017 (Two-barred Greenish Warbler, Elegant Tern, Yellow Warbler & a Richardson's Cackling Goose in Northumberland) & BOU (IOC) taxonomy have brought the English List to 503. The aim of this blog is to showcase both the excellent birds & other wildlife in the UK as well as abroad. Go out & have a look yourself. There is some great wildlife out there in the UK.I have travelled extensively abroad in all continents, except Antarctica. I saw my last Clements family, Sharpbill, in SE Brazil (Sept 04) joining a very exclusive group of birders to have seen at least one of each of the bird families of the world (taxonomic changes mean I need to see at least one of the 9 new families that have recently been recognised). I plan to see at least one of each of the new families by 2020. My World List is 6329 (Clements 2017 taxonomy). My Western Pale List is 703 (AERC taxonomy & BWP boundaries).The photos are protected from copying (as some bloggers have no scruples about stealing other peoples photos to make their dreary blogs look better). However, I will happily forward copies of the photos if you also saw the bird. Just ask using the comments option.